• Journal of Institute of Control, Robotics and Systems
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• v.13 no.11
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• pp.1082-1091
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• 2007

In this paper, we developed a new hybrid mobile robot which can climb stairs and go over thresholds by crawl gait with embedded real-time control software. This robot is also categorized into hybrid robot that has advantages of wheeled mobile robot and legged mobile robot, but adopts gait feature of crocodile named belly crawl. We imitated the belly crawl using four legs of 2 DOF, four omni-directional wheels, and embedded control software which controls legs and wheels. This software is developed using RTAI/Linux, real-time drivers. As a result, the new hybrid mobile robot has crawl gait. Using this feature, the new hybrid mobile robot can climb stairs and go over thresholds just by path planning of each leg with size of stairs and thresholds, and computing the movement distance of robot body center without considering stability. The performance of our new hybrid mobile robot is verified via experiments.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.110-113
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• 1999

In this paper. we propose an adaptive handover scheme in wireless network The proposed handover scheme is a hybrid type of virtual path extension and rerouting. The proposed handover scheme chooses the virtual path management scheme according to the service QoS instead of the network topology which is used in the previous hybrid handover schemes. The proposed scheme supports the seamless service and small buffering during virtual path rerouting handover through the multicasting service. To evaluate the performance of the proposed scheme. we compute the number of signaling message used for handover and perform computer simulation. The simulation results show that the proposed scheme provides more efficiency in the handover delay and seamless service than the previous methods.

• IE interfaces
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• v.22 no.4
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• pp.359-367
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• 2009

The vehicle travel time between the demand points in downtown area is greatly influenced by complex road condition and traffic situation that change real time to various external environments. Most of research in the vehicle routing problems compose vehicle routes only considering travel distance and average vehicle speed between the demand points, however did not consider dynamic external environments such as traffic situation by service time zones. A realistic vehicle routing problem which considers traffic situation of smooth, delaying, and stagnating by three service time zones such as going to work, afternoon, and going home was suggested in this study. A mathematical programming model was suggested and it gives an optimal solution when using ILOG CPLEX. A hybrid genetic algorithm was also suggested to chooses a vehicle route considering traffic situation to minimize the total travel time. By comparing the result considering the traffic situation, the suggested algorithm gives better solution than existing algorithms.

• The Journal of the Korea Contents Association
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• v.14 no.6
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• pp.453-465
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• 2014

Although fairly descent amount of research outcomes has been generated on problem-based learning(PBL) with regard to science and medical subjects, relatively less outcome has been generated on social science and management subjects. Therefore this study attempts to exam effect of problem-based learning in food service entrepreneurship subject on improving problem solving skills. After literature review, for constructing for this research frame, each class schedules were formed by hybrid-PEL and traditional lecture style respectively then problems, solution, and evaluation process were generated for hybrid-PBL. Through the result, there was hardly any differences occurred before and after traditional lecture approach on students' problem solving skills. There was, however, certain differences appeared on students' skills after hybrid-PBL approach. Through the study, hybrid-PBL learning can be an effective teaching method in social science and management subject for improving students' problem solving skill.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.749-750
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• 2013

Due to the rapid development of smart phones, smart phone users grew, expanding communication between the service users has been enabled by the application's service. Difficult to find a service that allows you to know the quality of school meals and the expectations of these applications. In addition, the existing application works only with a particular device, it is difficult to compatible devices. Thus, based on the HTML5 hybrid application were developed and this feed can be monitored by the students of the school, the communication can be formed.

• Proceedings of the Korean Information Science Society Conference
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• 2002.04a
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• pp.193-195
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• 2002

본 논문에서는 최근에 제안된 Hybrid 방식의 모바일 멀티캐스트 프로토콜 중 MOM, MMA, RBMOM, 그리고 TBMOM 프로토콜에 대해서 여러 가지 관점에서 성능을 비교하여 각 프로토콜의 장단점을 분석함과 동시에, 이들 방식이 공통적으로 가지는 DMSP(Designated Multicast Service Provider) 핸드오프 문제에 대해서 Smooth DMSP 핸드오프방식을 제안한다.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05a
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• pp.359-362
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• 2005

Self diagnosis monitoring system is defined as concrete structural carbon and glass hybrid fiber materials, in response to the change in external disturbance and environments, toward structural safety and serviceability as well as the extension of structural service life. In this study, carbon and glass hybrid fiber materials were investigated fundamentally for the applicability of self diagnosis in smart concrete structural system as embedded functions of sensors.

• Journal of the Korea Computer Industry Society
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• v.6 no.2
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• pp.345-354
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• 2005

Mobile grid can provide the grid service to grid users regardless of space and time. There are many restrictions to use grid service in mobile environment such as battery power of mobile device, movement pattern of mobile device etc. So it is difficult to apply the grid technologies of wired network to wireless network environments. Therefore, to provide the mobile grid service, we suggested the mobile grid architecture using ad-hoc network. Also we showed that hybrid routing protocol is efficient for mobile grid service by considering the battery power of mobile device and simulations of evaluating the delay time of three routing protocols using NS-2. We will study the methods of resource allocations and network reliability to provide the mobile grid service.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.11
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• pp.2143-2159
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• 2011

The hybrid architecture of content delivery networks (CDN) and peer-to-peer overlay networks (P2P) is a promising technology enables effective real-time streaming services. It complements the advantages of quality control and reliability in a CDN, and the scalability of a P2P system. With real-time streaming services, however, high connection setup and media delivery latency are becoming the critical issues in deploying the CDN-P2P system. These issues result from biased peer selection without location awareness or content awareness, and can lead to significant service disruption. To reduce service disruption latency, we propose a group-based CDN-P2P hybrid architecture (iCDN-P2P) with a location/content-aware selection of peers. Specifically, a SuperPeer network makes a location-aware peer selection by employing a content addressable network (CAN) to distribute channel information. It also manages peers with content awareness, forming a group of peers with the same channel as the sub-overlay. Through a performance evaluation, we show that the proposed architecture outperforms the original CDN-P2P hybrid architecture in terms of connection setup delay and media delivery time.

• Journal of Digital Contents Society
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• v.9 no.3
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• pp.509-516
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• 2008

We propose the Hybrid Rendering model to support multi-resolution for computer graphics. LOD method for computer graphics system considering performance of device environment and end-user preference usually adopts mesh resolution, mipmap in texture rendering, or oct-tree data structure in ray tracing. The hybrid rendering model, as a local shading model combining Gouraud shading model and a flat shading model, applies a proper shading method to each of polygons consisting of an object. This method can be an effective alternative to reduce real-time rendering time so that it can be utilized in real time adaptive service of computer graphic contents among various device environments under ubiquitous environments.